In the past, sealable containers, such as vials, have been used to collect, store and/or dispense liquids, such as a test sample of milk, urine, saliva or blood by way of example. The liquid sample may be collected in the vial at one site and then the vial is transported to another site where the liquid sample is removed from the vial and subjected to diagnostic testing.
Vials of the type to which the present invention relates are generally injection molded plastic vials that have caps adapted to seal the vial closed with a substantially fluid-tight seal. The cap may or may not be integrally connected to the vial, but oftentimes it is connected thereto by a flexible strap or tab.
Examples of several vials of this type and processes for making such vials are disclosed in U.S. Pat. Nos. 4,783,056, 4,812,116, 6,303,064 and RE 37,676 (a reissue of U.S. Pat. No. 5,723,085), all owned by the common assignee and each disclosure of which is hereby incorporated herein by reference in its entirety. Vials made according to these disclosed processes have the advantage of providing a reliable fluid-tight seal between the vial and the cap and may be made “sterile-by-process” wherein the heat from the molding process is used to maintain sterility while the cap is closed in the mold.
Other types of vials for collecting and transporting liquid samples include vials having a screw-on cap, such as disclosed in Davolt, U.S. Pat. No. 3,881,627. In the vial of Davolt, the vial is provided with screw threads on the outer portion of its neck. A V-shaped recess is provided in the lip of the vial and an upwardly facing, inclined, annular shoulder is provided on an inner wall of the neck. The cap has a cylindrical outer skirt and a shorter, inwardly spaced, inner cylindrical skirt adapted to be sealingly received against the annular shoulder provided on the inner wall of the neck to make sealing abutment therewith. An annular bead is provided on the cap between outer and inner skirts to seat against the V-shaped recess provided in the lip of the vial. The sealing approach of Davolt relies on plastic deformation of the inner skirt and the annular bead with their respective mating annular shoulder and V-shaped recess to provide a fluid-tight seal. One significant drawback of such a sealing approach is that the integrity of the various sealing engagements is compromised after the first use of the vial due to the plastic deformation of the parts. Consequently, such a vial may not provide a reliable fluid-tight seal to maintain the liquid sample within the vial following repeated openings and closings of the vial.
Accordingly, there is a need for an improved container having a cap for sealing the container that provides a reliable fluid-tight seal to contain a liquid sample within the container.